Method for annotating vvc subpictures in dash

ABSTRACT

There is included a method and apparatus comprising computer code configured to cause a processor or processors to impement obtaining a dynamic adaptive streaming over HTTP (DASH) video bitstream comprising one or more subpictures, determining whether the one or more subpictures include Versatile Video Coding (VVC) compliant subpictures, in response to the DASH video bitstream including the VVC compliant subpictures, annotating the one or more subpictures based on one or more flags, and manipulating the DASH video stream based on the annotated one or more subpictures.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to provisional applications U.S.63/298,924, filed on Jan. 12, 2022, the contents of which are herebyexpressly incorporated by reference, in their entirety, into the presentapplication.

BACKGROUND 1. Field

The present disclosure is directed to dynamic adaptive streaming overHTTP (DASH) signaling.

2. Description of Related Art

MPEG DASH provides a standard for streaming multimedia content over IPnetworks. ISO/IEC 23009-1 DASH standard allows the streaming of themulti-rate content. The DASH manifest, MPD, can describe various mediacontent. While the DASH standard provides a way to describe variouscontent and their relation, it does not provide an interoperablesolution to annotate the VVC subpictures to be used forpicture-in-picture applications.

SUMMARY

To address one or more different technical problems, this disclosureprovides technical solutions to reduce network overhead and servercomputational overheads, and there is included a method and apparatuscomprising memory configured to store computer program code and aprocessor or processors configured to access the computer program codeand operate as instructed by the computer program code. The computerprogram code comprises obtaining code configured to cause the at leastone processor to obtain a dynamic adaptive streaming over HTTP (DASH)video bitstream comprising one or more subpictures, determining codeconfigured to cause the at least one processor to determine whether theone or more subpictures include Versatile Video Coding (VVC) compliantsubpictures, annotating code configured to cause the at least oneprocessor to, in response to the DASH video bitstream including the VVCcompliant subpictures, annotate the one or more subpictures based on oneor more flags, and manipulating code configured to cause the at leastone processor to manipulate the DASH video stream based on the annotatedone or more subpictures.

According to exemplary embodiments, the video data is in dynamicadaptive streaming over HTTP (DASH), and the client is a DASH client.

According to exemplary embodiments, determining whether to annotate theone or more of the first subpictures and the second subpicturescomprises determining whether to annotate the one or more of the firstsubpictures and the second subpictures in a DASH media picturedescription (MPD).

According to exemplary embodiments, the other of the first stream andthe second stream comprises a picture-in-picture (PIP) stream.

According to exemplary embodiments, controlling the client to replacethe at least part of the one of the first stream and the second streamcomprises replacing an area represented by a plurality of ones of thefirst subpictures and the second subpictures with the PIP stream.

According to exemplary embodiments, the one of the first stream and thesecond stream represents a main video and the other of the first streamand the second stream represents a separately coded stream as asupplementary video to the main video.

According to exemplary embodiments, controlling the client to replacethe at least part of the one of the first stream and the second streamcomprises determining whether a user requested to view the supplementaryvideo.

According to exemplary embodiments, the main video and the supplementaryvideo each comprise versatile video coding (VVC) subpictures.

According to exemplary embodiments, controlling the client to replacethe at least part of the one of the first stream and the second streamcomprises merging properties of versatile video coding (VVC) subpicturessuch that a decoder is provided with a single merged stream merged fromboth of the first stream and the second stream.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features, nature, and various advantages of the disclosedsubject matter will be more apparent from the following detaileddescription and the accompanying drawings in which:

FIG. 1 is a simplified schematic illustration in accordance withembodiments.

FIG. 2 is a simplified schematic illustration in accordance withembodiments.

FIG. 3 is a simplified block diagram regarding decoders in accordancewith embodiments.

FIG. 4 is a simplified block diagram regarding encoders in accordancewith embodiments.

FIG. 5 is a simplified block diagram in accordance with embodiments.

FIG. 6 is a simplified diagram in accordance with embodiments.

FIG. 7 is a simplified diagram in accordance with embodiments.

FIG. 8 is a simplified flow diagram in accordance with embodiments.

FIG. 9 is a schematic illustration in accordance with embodiments.

DETAILED DESCRIPTION

The proposed features discussed below may be used separately or combinedin any order. Further, the embodiments may be implemented by processingcircuitry (e.g., one or more processors or one or more integratedcircuits). In one example, the one or more processors execute a programthat is stored in a non-transitory computer-readable medium.

FIG. 1 illustrates a simplified block diagram of a communication system100 according to an embodiment of the present disclosure. Thecommunication system 100 may include at least two terminals 102 and 103interconnected via a network 105. For unidirectional transmission ofdata, a first terminal 103 may code video data at a local location fortransmission to the other terminal 102 via the network 105. The secondterminal 102 may receive the coded video data of the other terminal fromthe network 105, decode the coded data and display the recovered videodata. Unidirectional data transmission may be common in media servingapplications and the like.

FIG. 1 illustrates a second pair of terminals 101 and 104 provided tosupport bidirectional transmission of coded video that may occur, forexample, during videoconferencing. For bidirectional transmission ofdata, each terminal 101 and 104 may code video data captured at a locallocation for transmission to the other terminal via the network 105.Each terminal 101 and 104 also may receive the coded video datatransmitted by the other terminal, may decode the coded data and maydisplay the recovered video data at a local display device.

In FIG. 1 , the terminals 101, 102, 103 and 104 may be illustrated asservers, personal computers and smart phones but the principles of thepresent disclosure are not so limited. Embodiments of the presentdisclosure find application with laptop computers, tablet computers,media players and/or dedicated video conferencing equipment. The network105 represents any number of networks that convey coded video data amongthe terminals 101, 102, 103 and 104, including for example wirelineand/or wireless communication networks. The communication network 105may exchange data in circuit-switched and/or packet-switched channels.Representative networks include telecommunications networks, local areanetworks, wide area networks and/or the Internet. For the purposes ofthe present discussion, the architecture and topology of the network 105may be immaterial to the operation of the present disclosure unlessexplained herein below.

FIG. 2 illustrates, as an example for an application for the disclosedsubject matter, the placement of a video encoder and decoder in astreaming environment. The disclosed subject matter can be equallyapplicable to other video enabled applications, including, for example,video conferencing, digital TV, storing of compressed video on digitalmedia including CD, DVD, memory stick and the like, and so on.

A streaming system may include a capture subsystem 203, that can includea video source 201, for example a digital camera, creating, for example,an uncompressed video sample stream 213. That sample stream 213 may beemphasized as a high data volume when compared to encoded videobitstreams and can be processed by an encoder 202 coupled to the camera201. The encoder 202 can include hardware, software, or a combinationthereof to enable or implement aspects of the disclosed subject matteras described in more detail below. The encoded video bitstream 204,which may be emphasized as a lower data volume when compared to thesample stream, can be stored on a streaming server 205 for future use.One or more streaming clients 212 and 207 can access the streamingserver 205 to retrieve copies 208 and 206 of the encoded video bitstream204. A client 212 can include a video decoder 211 which decodes theincoming copy of the encoded video bitstream 208 and creates an outgoingvideo sample stream 210 that can be rendered on a display 209 or otherrendering device (not depicted). In some streaming systems, the videobitstreams 204, 206 and 208 can be encoded according to certain videocoding/compression standards. Examples of those standards are notedabove and described further herein.

FIG. 3 may be a functional block diagram of a video decoder 300according to an embodiment of the present invention.

A receiver 302 may receive one or more codec video sequences to bedecoded by the decoder 300; in the same or another embodiment, one codedvideo sequence at a time, where the decoding of each coded videosequence is independent from other coded video sequences. The codedvideo sequence may be received from a channel 301, which may be ahardware/software link to a storage device which stores the encodedvideo data. The receiver 302 may receive the encoded video data withother data, for example, coded audio data and/or ancillary data streams,that may be forwarded to their respective using entities (not depicted).The receiver 302 may separate the coded video sequence from the otherdata. To combat network jitter, a buffer memory 303 may be coupled inbetween receiver 302 and entropy decoder/parser 304 (“parser”henceforth). When receiver 302 is receiving data from a store/forwarddevice of sufficient bandwidth and controllability, or from anisosychronous network, the buffer 303 may not be needed, or can besmall. For use on best effort packet networks such as the Internet, thebuffer 303 may be required, can be comparatively large and canadvantageously of adaptive size.

The video decoder 300 may include a parser 304 to reconstruct symbols313 from the entropy coded video sequence. Categories of those symbolsinclude information used to manage operation of the decoder 300, andpotentially information to control a rendering device such as a display312 that is not an integral part of the decoder but can be coupled toit. The control information for the rendering device(s) may be in theform of Supplementary Enhancement Information (SEI messages) or VideoUsability Information parameter set fragments (not depicted). The parser304 may parse/entropy-decode the coded video sequence received. Thecoding of the coded video sequence can be in accordance with a videocoding technology or standard, and can follow principles well known to aperson skilled in the art, including variable length coding, Huffmancoding, arithmetic coding with or without context sensitivity, and soforth. The parser 304 may extract from the coded video sequence, a setof subgroup parameters for at least one of the subgroups of pixels inthe video decoder, based upon at least one parameters corresponding tothe group. Subgroups can include Groups of Pictures (GOPs), pictures,tiles, slices, macroblocks, Coding Units (CUs), blocks, Transform Units(TUs), Prediction Units (PUs) and so forth. The entropy decoder/parsermay also extract from the coded video sequence information such astransform coefficients, quantizer parameter values, motion vectors, andso forth.

The parser 304 may perform entropy decoding/parsing operation on thevideo sequence received from the buffer 303, so to create symbols 313.The parser 304 may receive encoded data, and selectively decodeparticular symbols 313. Further, the parser 304 may determine whetherthe particular symbols 313 are to be provided to a Motion CompensationPrediction unit 306, a scaler/inverse transform unit 305, an IntraPrediction Unit 307, or a loop filter 311.

Reconstruction of the symbols 313 can involve multiple different unitsdepending on the type of the coded video picture or parts thereof (suchas: inter and intra picture, inter and intra block), and other factors.Which units are involved, and how, can be controlled by the subgroupcontrol information that was parsed from the coded video sequence by theparser 304. The flow of such subgroup control information between theparser 304 and the multiple units below is not depicted for clarity.

Beyond the functional blocks already mentioned, decoder 300 can beconceptually subdivided into a number of functional units as describedbelow. In a practical implementation operating under commercialconstraints, many of these units interact closely with each other andcan, at least partly, be integrated into each other. However, for thepurpose of describing the disclosed subject matter, the conceptualsubdivision into the functional units below is appropriate.

A first unit is the scaler/inverse transform unit 305. Thescaler/inverse transform unit 305 receives quantized transformcoefficient as well as control information, including which transform touse, block size, quantization factor, quantization scaling matrices,etc. as symbol(s) 313 from the parser 304. It can output blockscomprising sample values, that can be input into aggregator 310.

In some cases, the output samples of the scaler/inverse transform 305can pertain to an intra coded block; that is: a block that is not usingpredictive information from previously reconstructed pictures, but canuse predictive information from previously reconstructed parts of thecurrent picture. Such predictive information can be provided by an intrapicture prediction unit 307. In some cases, the intra picture predictionunit 307 generates a block of the same size and shape of the block underreconstruction, using surrounding already reconstructed informationfetched from the current (partly reconstructed) picture 309. Theaggregator 310, in some cases, adds, on a per sample basis, theprediction information the intra prediction unit 307 has generated tothe output sample information as provided by the scaler/inversetransform unit 305.

In other cases, the output samples of the scaler/inverse transform unit305 can pertain to an inter coded, and potentially motion compensatedblock. In such a case, a Motion Compensation Prediction unit 306 canaccess reference picture memory 308 to fetch samples used forprediction. After motion compensating the fetched samples in accordancewith the symbols 313 pertaining to the block, these samples can be addedby the aggregator 310 to the output of the scaler/inverse transform unit(in this case called the residual samples or residual signal) so togenerate output sample information. The addresses within the referencepicture memory form where the motion compensation unit fetchesprediction samples can be controlled by motion vectors, available to themotion compensation unit in the form of symbols 313 that can have, forexample X, Y, and reference picture components. Motion compensation alsocan include interpolation of sample values as fetched from the referencepicture memory when sub-sample exact motion vectors are in use, motionvector prediction mechanisms, and so forth.

The output samples of the aggregator 310 can be subject to various loopfiltering techniques in the loop filter unit 311. Video compressiontechnologies can include in-loop filter technologies that are controlledby parameters included in the coded video bitstream and made availableto the loop filter unit 311 as symbols 313 from the parser 304, but canalso be responsive to meta-information obtained during the decoding ofprevious (in decoding order) parts of the coded picture or coded videosequence, as well as responsive to previously reconstructed andloop-filtered sample values.

The output of the loop filter unit 311 can be a sample stream that canbe output to the render device 312 as well as stored in the referencepicture memory 557 for use in future inter-picture prediction.

Certain coded pictures, once fully reconstructed, can be used asreference pictures for future prediction. Once a coded picture is fullyreconstructed and the coded picture has been identified as a referencepicture (by, for example, parser 304), the current reference picture 309can become part of the reference picture buffer 308, and a fresh currentpicture memory can be reallocated before commencing the reconstructionof the following coded picture.

The video decoder 300 may perform decoding operations according to apredetermined video compression technology that may be documented in astandard, such as ITU-T Rec. H.265. The coded video sequence may conformto a syntax specified by the video compression technology or standardbeing used, in the sense that it adheres to the syntax of the videocompression technology or standard, as specified in the videocompression technology document or standard and specifically in theprofiles document therein. Also necessary for compliance can be that thecomplexity of the coded video sequence is within bounds as defined bythe level of the video compression technology or standard. In somecases, levels restrict the maximum picture size, maximum frame rate,maximum reconstruction sample rate (measured in, for example megasamplesper second), maximum reference picture size, and so on. Limits set bylevels can, in some cases, be further restricted through HypotheticalReference Decoder (HRD) specifications and metadata for HRD buffermanagement signaled in the coded video sequence.

In an embodiment, the receiver 302 may receive additional (redundant)data with the encoded video. The additional data may be included as partof the coded video sequence(s). The additional data may be used by thevideo decoder 300 to properly decode the data and/or to more accuratelyreconstruct the original video data. Additional data can be in the formof, for example, temporal, spatial, or signal-to-noise ratio (SNR)enhancement layers, redundant slices, redundant pictures, forward errorcorrection codes, and so on.

FIG. 4 may be a functional block diagram of a video encoder 400according to an embodiment of the present disclosure.

The encoder 400 may receive video samples from a video source 401 (thatis not part of the encoder) that may capture video image(s) to be codedby the encoder 400.

The video source 401 may provide the source video sequence to be codedby the encoder (303) in the form of a digital video sample stream thatcan be of any suitable bit depth (for example: 8 bit, 10 bit, 12 bit, .. . ), any colorspace (for example, BT.601 Y CrCB, RGB, . . . ) and anysuitable sampling structure (for example Y CrCb 4:2:0, Y CrCb 4:4:4). Ina media serving system, the video source 401 may be a storage devicestoring previously prepared video. In a videoconferencing system, thevideo source 401 may be a camera that captures local image informationas a video sequence. Video data may be provided as a plurality ofindividual pictures that impart motion when viewed in sequence. Thepictures themselves may be organized as a spatial array of pixels,wherein each pixel can comprise one or more samples depending on thesampling structure, color space, etc. in use. A person skilled in theart can readily understand the relationship between pixels and samples.The description below focuses on samples.

According to an embodiment, the encoder 400 may code and compress thepictures of the source video sequence into a coded video sequence 410 inreal time or under any other time constraints as required by theapplication. Enforcing appropriate coding speed is one function ofController 402. Controller controls other functional units as describedbelow and is functionally coupled to these units. The coupling is notdepicted for clarity. Parameters set by controller can include ratecontrol related parameters (picture skip, quantizer, lambda value ofrate-distortion optimization techniques, . . . ), picture size, group ofpictures (GOP) layout, maximum motion vector search range, and so forth.A person skilled in the art can readily identify other functions ofcontroller 402 as they may pertain to video encoder 400 optimized for acertain system design.

Some video encoders operate in what a person skilled in the art readilyrecognizes as a “coding loop.” As an oversimplified description, acoding loop can consist of the encoding part of an encoder 402 (“sourcecoder” henceforth) (responsible for creating symbols based on an inputpicture to be coded, and a reference picture(s)), and a (local) decoder406 embedded in the encoder 400 that reconstructs the symbols to createthe sample data that a (remote) decoder also would create (as anycompression between symbols and coded video bitstream is lossless in thevideo compression technologies considered in the disclosed subjectmatter). That reconstructed sample stream is input to the referencepicture memory 405. As the decoding of a symbol stream leads tobit-exact results independent of decoder location (local or remote), thereference picture buffer content is also bit exact between local encoderand remote encoder. In other words, the prediction part of an encoder“sees” as reference picture samples exactly the same sample values as adecoder would “see” when using prediction during decoding. Thisfundamental principle of reference picture synchronicity (and resultingdrift, if synchronicity cannot be maintained, for example because ofchannel errors) is well known to a person skilled in the art.

The operation of the “local” decoder 406 can be the same as of a“remote” decoder 300, which has already been described in detail abovein conjunction with FIG. 3 . Briefly referring also to FIG. 4 , however,as symbols are available and en/decoding of symbols to a coded videosequence by entropy coder 408 and parser 304 can be lossless, theentropy decoding parts of decoder 300, including channel 301, receiver302, buffer 303, and parser 304 may not be fully implemented in localdecoder 406.

An observation that can be made at this point is that any decodertechnology except the parsing/entropy decoding that is present in adecoder also necessarily needs to be present, in substantially identicalfunctional form, in a corresponding encoder. The description of encodertechnologies can be abbreviated as they are the inverse of thecomprehensively described decoder technologies. Only in certain areas amore detail description is required and provided below.

As part of its operation, the source coder 403 may perform motioncompensated predictive coding, which codes an input frame predictivelywith reference to one or more previously-coded frames from the videosequence that were designated as “reference frames.” In this manner, thecoding engine 407 codes differences between pixel blocks of an inputframe and pixel blocks of reference frame(s) that may be selected asprediction reference(s) to the input frame.

The local video decoder 406 may decode coded video data of frames thatmay be designated as reference frames, based on symbols created by thesource coder 403. Operations of the coding engine 407 may advantageouslybe lossy processes. When the coded video data may be decoded at a videodecoder (not shown in FIG. 4 ), the reconstructed video sequencetypically may be a replica of the source video sequence with someerrors. The local video decoder 406 replicates decoding processes thatmay be performed by the video decoder on reference frames and may causereconstructed reference frames to be stored in the reference picturecache 405. In this manner, the encoder 400 may store copies ofreconstructed reference frames locally that have common content as thereconstructed reference frames that will be obtained by a far-end videodecoder (absent transmission errors).

The predictor 404 may perform prediction searches for the coding engine407. That is, for a new frame to be coded, the predictor 404 may searchthe reference picture memory 405 for sample data (as candidate referencepixel blocks) or certain metadata such as reference picture motionvectors, block shapes, and so on, that may serve as an appropriateprediction reference for the new pictures. The predictor 404 may operateon a sample block-by-pixel block basis to find appropriate predictionreferences. In some cases, as determined by search results obtained bythe predictor 404, an input picture may have prediction references drawnfrom multiple reference pictures stored in the reference picture memory405.

The controller 402 may manage coding operations of the video coder 403,including, for example, setting of parameters and subgroup parametersused for encoding the video data.

Output of all aforementioned functional units may be subjected toentropy coding in the entropy coder 408. The entropy coder translatesthe symbols as generated by the various functional units into a codedvideo sequence, by loss-less compressing the symbols according totechnologies known to a person skilled in the art as, for exampleHuffman coding, variable length coding, arithmetic coding, and so forth.

The transmitter 409 may buffer the coded video sequence(s) as created bythe entropy coder 408 to prepare it for transmission via a communicationchannel 411, which may be a hardware/software link to a storage devicewhich would store the encoded video data. The transmitter 409 may mergecoded video data from the video coder 403 with other data to betransmitted, for example, coded audio data and/or ancillary data streams(sources not shown).

The controller 402 may manage operation of the encoder 400. Duringcoding, the controller 405 may assign to each coded picture a certaincoded picture type, which may affect the coding techniques that may beapplied to the respective picture. For example, pictures often may beassigned as one of the following frame types:

An Intra Picture (I picture) may be one that may be coded and decodedwithout using any other frame in the sequence as a source of prediction.Some video codecs allow for different types of Intra pictures,including, for example Independent Decoder Refresh Pictures. A personskilled in the art is aware of those variants of I pictures and theirrespective applications and features.

A Predictive picture (P picture) may be one that may be coded anddecoded using intra prediction or inter prediction using at most onemotion vector and reference index to predict the sample values of eachblock.

A Bi-directionally Predictive Picture (B Picture) may be one that may becoded and decoded using intra prediction or inter prediction using atmost two motion vectors and reference indices to predict the samplevalues of each block. Similarly, multiple-predictive pictures can usemore than two reference pictures and associated metadata for thereconstruction of a single block.

Source pictures commonly may be subdivided spatially into a plurality ofsample blocks (for example, blocks of 4×4, 8×8, 4×8, or 16×16 sampleseach) and coded on a block-by-block basis. Blocks may be codedpredictively with reference to other (already coded) blocks asdetermined by the coding assignment applied to the blocks' respectivepictures. For example, blocks of I pictures may be codednon-predictively or they may be coded predictively with reference toalready coded blocks of the same picture (spatial prediction or intraprediction). Pixel blocks of P pictures may be coded non-predictively,via spatial prediction or via temporal prediction with reference to onepreviously coded reference pictures. Blocks of B pictures may be codednon-predictively, via spatial prediction or via temporal prediction withreference to one or two previously coded reference pictures.

The video coder 400 may perform coding operations according to apredetermined video coding technology or standard, such as ITU-T Rec.H.265. In its operation, the video coder 400 may perform variouscompression operations, including predictive coding operations thatexploit temporal and spatial redundancies in the input video sequence.The coded video data, therefore, may conform to a syntax specified bythe video coding technology or standard being used.

In an embodiment, the transmitter 409 may transmit additional data withthe encoded video. The source coder 403 may include such data as part ofthe coded video sequence. Additional data may comprisetemporal/spatial/SNR enhancement layers, other forms of redundant datasuch as redundant pictures and slices, Supplementary EnhancementInformation (SEI) messages, Visual Usability Information (VUI) parameterset fragments, and so on.

FIG. 5 shows a sample DASH client processing model 500, such as of aclient sample architecture for processing DASH and Common MediaApplication Format (CMAF) events, in which a client request of mediasegments may be based on described addresses in a manifest which alsodescribed metadata tracks from which a client may access segments ofmetadata tracks, parse them, and send them to an application. Further,according to exemplary embodiments, of addresses for media segments suchas described below, a DASH manifest may provide addressed for Indexsegments. Each index segment may provide information about one segmentduration and size, and a Representation Index may provide the indexinformation for all segments of a given representation.

FIG. 6 shows an example 600 of a picture-in-picture use case such that amain picture may take up an entire screen, such as a window display oraugmented reality view or the like, while the overlay picture,picture-in-picture, takes a small area of the screen, covering thecorresponding area of the main picture. The coordinate of thepicture-in-picture (pip) is indicated by x, y, height, and width, wherethese parameters define the location and size of the pip relative to themain picture coordinate correspondingly.

Viewing the example 700 in FIG. 7 and the flowchart 800 in FIG. 8 , itwill be understood that according to exemplary embodiments, in the caseof streaming, a main video and a pip video may be delivered as twoseparate streams at S801 such as from different servers or at leastdifferent sources such as in video conferencing or the like. And thosestreams may be delivered as otherwise independent streams to be aredecoded by separate decoders at S804 after determining No as to thedetermination at S802, or directly from S801, and then composed togetherfor rendering. But, according to exemplary embodiments, when the usedvideo codec supports merging the streams, it may be determined at S802such as by a flag included with one or more of the video streams, and/oras metadata thereof, having the respective subpictures at S801, the pipvideo stream may be combined with the main video stream at S803,possibly replacing the streaming that represents the covered area of themain video with the pip video, and then the single stream is, at S804,sent to the decoder for decoding and then rendering. And thereby atechnical burden on the decoder is reduced as the single, merged streammay be delivered for decoding rather than the initial, independentstreams to be separately decoded and then merged.

According to exemplary embodiments, such as with example 700 and example800, VVC subpictures can be used for picture-in-picture services byusing both the extraction and merging properties of VVC subpictures. Forsuch a service, the main video is encoded using several subpictures, oneof them of the same size as a supplementary video, located at the exactlocation where the supplementary video is intended to be composited intothe main video and coded independently to enable extraction. If a userchooses, such as at S802, to view the version of the service thatincludes the supplementary video, the subpicture that corresponds to thepicture-in-picture area of the main video is extracted from the mainvideo bitstream, and the supplementary video bitstream is merged withthe main video bitstream in its place, as illustrated in the example 700and example 800 but with the above-described decoding replaced withencoding as will be understood for the purpose of such exemplaryembodiments regarding encoding.

And the above-described annotation to one or more subpicture propertiesof VVC in DASH, such as at S802 and S803, may uses an MPDContentComponent element to describe the properties of varioussubpictures of a VVC stream according to exemplary embodiments. Forexample, a use of such element may be understood from the followingTable 1:

TABLE 1 Semantics of ContentComponent element used for VVC subpictureannotation according to exemplary embodiments Element or Attribute NameUse Description ContentComponent Description of a content component. @idO The id of the subpicture. @contentType O video @tag O The valueindicates the property and priority of the subpicture. For picture inpicture replacement, the value consists of the string ‘PIP’ followed bya positive integer number. The number indicates the priority of thecorresponding subpicture to be replaced. For example, PIP1 should be thefirst subpicture to be replaced before PIP2. Role 0 . . . N The valueindicates the application suitability of the subpicture. For instance,the value “sign” for a subpicture shows it is suitable to be replacedwith a signed language video. Key For attributes: M = mandatory, O =optional, OD = optional with default value, CM = conditionallymandatory, F = fixed For elements: <minOccurs> . . . <maxOccurs> (N =unbounded) Elements are bold; attributes are non-bold and preceded withan @; list of elements and attributes is in italics bold referring tothose taken from the Base type that has been extended by this type.

And according to exemplary embodiments, any VVC subpicture, aContentComponent element can be added into the adaptation set orrepresentation, annotating that subpicture. And the DASH client canprovide the annotation to a bitstream manipulator to replace the desiredsubpicture stream with the picture-in-picture video stream and then feedthe manipulated VVC bitstream to the VVC decoder according to exemplaryembodiments.

Further, embodiments herein extend to other codecs such that theembodiments herein can be used for other video streams that consist ofsuch subpictures, and a same method(s) as described above can be usedfor any audio or media stream that consists of multiple substreams thatcan be independently decoded. That is, each substream can be annotatedusing any one or more of the above methods which thereby at least reducea coding burden.

The techniques described above, can be implemented as computer softwareusing computer-readable instructions and physically stored in one ormore computer-readable media or by a specifically configured one or morehardware processors. For example, FIG. 9 shows a computer system 900suitable for implementing certain embodiments of the disclosed subjectmatter.

The computer software can be coded using any suitable machine code orcomputer language, that may be subject to assembly, compilation,linking, or like mechanisms to create code comprising instructions thatcan be executed directly, or through interpretation, micro-codeexecution, and the like, by computer central processing units (CPUs),Graphics Processing Units (GPUs), and the like.

The instructions can be executed on various types of computers orcomponents thereof, including, for example, personal computers, tabletcomputers, servers, smartphones, gaming devices, internet of thingsdevices, and the like.

The components shown in FIG. 9 for computer system 900 are exemplary innature and are not intended to suggest any limitation as to the scope ofuse or functionality of the computer software implementing embodimentsof the present disclosure. Neither should the configuration ofcomponents be interpreted as having any dependency or requirementrelating to any one or combination of components illustrated in theexemplary embodiment of a computer system 900.

Computer system 900 may include certain human interface input devices.Such a human interface input device may be responsive to input by one ormore human users through, for example, tactile input (such as:keystrokes, swipes, data glove movements), audio input (such as: voice,clapping), visual input (such as: gestures), olfactory input (notdepicted). The human interface devices can also be used to capturecertain media not necessarily directly related to conscious input by ahuman, such as audio (such as: speech, music, ambient sound), images(such as: scanned images, photographic images obtain from a still imagecamera), video (such as two-dimensional video, three-dimensional videoincluding stereoscopic video).

Input human interface devices may include one or more of (only one ofeach depicted): keyboard 901, mouse 902, trackpad 903, touch screen 910,joystick 905, microphone 906, scanner 908, camera 907.

Computer system 900 may also include certain human interface outputdevices. Such human interface output devices may be stimulating thesenses of one or more human users through, for example, tactile output,sound, light, and smell/taste. Such human interface output devices mayinclude tactile output devices (for example tactile feedback by thetouch-screen 910, or joystick 905, but there can also be tactilefeedback devices that do not serve as input devices), audio outputdevices (such as: speakers 909, headphones (not depicted)), visualoutput devices (such as screens 910 to include CRT screens, LCD screens,plasma screens, OLED screens, each with or without touch-screen inputcapability, each with or without tactile feedback capability— some ofwhich may be capable to output two dimensional visual output or morethan three dimensional output through means such as stereographicoutput; virtual-reality glasses (not depicted), holographic displays andsmoke tanks (not depicted)), and printers (not depicted).

Computer system 900 can also include human accessible storage devicesand their associated media such as optical media including CD/DVD ROM/RW920 with CD/DVD 911 or the like media, thumb-drive 922, removable harddrive or solid state drive 923, legacy magnetic media such as tape andfloppy disc (not depicted), specialized ROM/ASIC/PLD based devices suchas security dongles (not depicted), and the like.

Those skilled in the art should also understand that term “computerreadable media” as used in connection with the presently disclosedsubject matter does not encompass transmission media, carrier waves, orother transitory signals.

Computer system 900 can also include interface 999 to one or morecommunication networks 998. Networks 998 can for example be wireless,wireline, optical. Networks 998 can further be local, wide-area,metropolitan, vehicular and industrial, real-time, delay-tolerant, andso on. Examples of networks 998 include local area networks such asEthernet, wireless LANs, cellular networks to include GSM, 3G, 4G, 5G,LTE and the like, TV wireline or wireless wide area digital networks toinclude cable TV, satellite TV, and terrestrial broadcast TV, vehicularand industrial to include CANBus, and so forth. Certain networks 998commonly require external network interface adapters that attached tocertain general-purpose data ports or peripheral buses (950 and 951)(such as, for example USB ports of the computer system 900; others arecommonly integrated into the core of the computer system 900 byattachment to a system bus as described below (for example Ethernetinterface into a PC computer system or cellular network interface into asmartphone computer system). Using any of these networks 998, computersystem 900 can communicate with other entities. Such communication canbe uni-directional, receive only (for example, broadcast TV),uni-directional send-only (for example CANbusto certain CANbus devices),or bi-directional, for example to other computer systems using local orwide area digital networks. Certain protocols and protocol stacks can beused on each of those networks and network interfaces as describedabove.

Aforementioned human interface devices, human-accessible storagedevices, and network interfaces can be attached to a core 940 of thecomputer system 900.

The core 940 can include one or more Central Processing Units (CPU) 941,Graphics Processing Units (GPU) 942, a graphics adapter 917, specializedprogrammable processing units in the form of Field Programmable GateAreas (FPGA) 943, hardware accelerators for certain tasks 944, and soforth. These devices, along with Read-only memory (ROM) 945,Random-access memory 946, internal mass storage such as internalnon-user accessible hard drives, SSDs, and the like 947, may beconnected through a system bus 948. In some computer systems, the systembus 948 can be accessible in the form of one or more physical plugs toenable extensions by additional CPUs, GPU, and the like. The peripheraldevices can be attached either directly to the core's system bus 948, orthrough a peripheral bus 951. Architectures for a peripheral bus includePCI, USB, and the like.

CPUs 941, GPUs 942, FPGAs 943, and accelerators 944 can execute certaininstructions that, in combination, can make up the aforementionedcomputer code. That computer code can be stored in ROM 945 or RAM 946.Transitional data can be also be stored in RAM 946, whereas permanentdata can be stored for example, in the internal mass storage 947. Faststorage and retrieval to any of the memory devices can be enabledthrough the use of cache memory, that can be closely associated with oneor more CPU 941, GPU 942, mass storage 947, ROM 945, RAM 946, and thelike.

The computer readable media can have computer code thereon forperforming various computer-implemented operations. The media andcomputer code can be those specially designed and constructed for thepurposes of the present disclosure, or they can be of the kind wellknown and available to those having skill in the computer software arts.

As an example and not by way of limitation, an architecturecorresponding to computer system 900, and specifically the core 940 canprovide functionality as a result of processor(s) (including CPUs, GPUs,FPGA, accelerators, and the like) executing software embodied in one ormore tangible, computer-readable media. Such computer-readable media canbe media associated with user-accessible mass storage as introducedabove, as well as certain storage of the core 940 that are ofnon-transitory nature, such as core-internal mass storage 947 or ROM945. The software implementing various embodiments of the presentdisclosure can be stored in such devices and executed by core 940. Acomputer-readable medium can include one or more memory devices orchips, according to particular needs. The software can cause the core940 and specifically the processors therein (including CPU, GPU, FPGA,and the like) to execute particular processes or particular parts ofparticular processes described herein, including defining datastructures stored in RAM 946 and modifying such data structuresaccording to the processes defined by the software. In addition or as analternative, the computer system can provide functionality as a resultof logic hardwired or otherwise embodied in a circuit (for example:accelerator 944), which can operate in place of or together withsoftware to execute particular processes or particular parts ofparticular processes described herein. Reference to software canencompass logic, and vice versa, where appropriate. Reference to acomputer-readable media can encompass a circuit (such as an integratedcircuit (IC)) storing software for execution, a circuit embodying logicfor execution, or both, where appropriate. The present disclosureencompasses any suitable combination of hardware and software.

While this disclosure has described several exemplary embodiments, thereare alterations, permutations, and various substitute equivalents, whichfall within the scope of the disclosure. It will thus be appreciatedthat those skilled in the art will be able to devise numerous systemsand methods which, although not explicitly shown or described herein,embody the principles of the disclosure and are thus within the spiritand scope thereof.

What is claimed is:
 1. A method of video coding, the method comprising:obtaining a dynamic adaptive streaming over HTTP (DASH) video bitstreamcomprising one or more subpictures; determining whether the one or moresubpictures include Versatile Video Coding (VVC) compliant subpictures;in response to the DASH video bitstream including the VVC compliantsubpictures, annotating the one or more subpictures based on one or moreflags; and manipulating the DASH video stream based on the annotated oneor more subpictures.
 2. The method according to claim 1, wherein the oneor more subpictures are of a first and second stream of subpictures,wherein the method comprises controlling a client to replace at leastpart of one of the first stream and the second stream with another oneof the first stream and the second stream based on the annotated one ormore subpictures, wherein the video data comprises dynamic adaptivestreaming over HTTP (DASH) video data, and wherein the client is a DASHclient.
 3. The method according to claim 2, wherein the method furthercomprises determining whether to annotate the one or more of the firstsubpictures and the second subpictures comprises determining whether toannotate the one or more of the first subpictures and the secondsubpictures in a DASH media picture description (MPD).
 4. The methodaccording to claim 2, wherein the other of the first stream and thesecond stream comprises a picture-in-picture (PIP) stream.
 5. The methodaccording to claim 4, wherein the controlling of the client to replacethe at least part of the one of the first stream and the second streamcomprises replacing an area represented by a plurality of ones of thefirst subpictures and the second subpictures with the PIP stream.
 6. Themethod according to claim 5, wherein the one of the first stream and thesecond stream represents a main video and the other of the first streamand the second stream represents a separately coded stream as asupplementary video to the main video.
 7. The method according to claim6, wherein the controlling of the client to replace the at least part ofthe one of the first stream and the second stream comprises determiningwhether a user requested to view the supplementary video.
 8. The methodaccording to claim 7, wherein the main video and the supplementary videoeach comprise versatile video coding (VVC) subpictures.
 9. The methodaccording to claim 2, wherein the controlling of the client to replacethe at least part of the one of the first stream and the second streamcomprises merging properties of VVC subpictures such that a decoder isprovided with a single merged stream merged from both of the firststream and the second stream.
 10. The method according to claim 2,wherein the obtaining of the video data comprises obtaining the firststream separately from the second stream.
 11. A apparatus for videostreaming, the apparatus comprising: at least one memory configured tostore computer program code; at least one processor configured to accessthe computer program code and operate as instructed by the computerprogram code, the computer program code including: obtaining codeconfigured to cause the at least one processor to obtain a dynamicadaptive streaming over HTTP (DASH) video bitstream comprising one ormore subpictures; determining code configured to cause the at least oneprocessor to determine whether the one or more subpictures includeVersatile Video Coding (VVC) compliant subpictures; annotating codeconfigured to cause the at least one processor to, in response to theDASH video bitstream including the VVC compliant subpictures, annotatethe one or more subpictures based on one or more flags; and manipulatingcode configured to cause the at least one processor to manipulate theDASH video stream based on the annotated one or more subpictures. 12.The apparatus according to claim 11, wherein the one or more subpicturesare of a first and second stream of subpictures, wherein the computercode further includes controlling code configured to cause the at leastone processor to control a client to replace at least part of one of thefirst stream and the second stream with another one of the first streamand the second stream based on the annotated one or more subpictures,wherein the video data comprises dynamic adaptive streaming over HTTP(DASH) video data, and wherein the client is a DASH client.
 13. Theapparatus according to claim 12, wherein the determining code is furtherconfigured to cause the at least one processor to determine whether toannotate the one or more of the first subpictures and the secondsubpictures in a DASH media picture description (MPD).
 14. The apparatusaccording to claim 12, wherein the other of the first stream and thesecond stream comprises a picture-in-picture (PIP) stream.
 15. Theapparatus according to claim 14, wherein the controlling code is furtherconfigured to cause the at least one processor to replace an arearepresented by a plurality of ones of the first subpictures and thesecond subpictures with the PIP stream.
 16. The apparatus according toclaim 15, wherein the one of the first stream and the second streamrepresents a main video and the other of the first stream and the secondstream represents a separately coded stream as a supplementary video tothe main video.
 17. The apparatus according to claim 16, wherein thecontrolling code is further configured to cause the at least oneprocessor to determine whether a user requested to view thesupplementary video.
 18. The apparatus according to claim 17, whereinthe main video and the supplementary video each comprise versatile videocoding (VVC) subpictures.
 19. The apparatus according to claim 12,wherein the controlling code is further configured to cause the at leastone processor to merge properties of VVC subpictures such that a decoderis provided with a single merged stream merged from both of the firststream and the second stream.
 20. A non-transitory computer readablemedium storing a program causing a computer to execute a process, theprocess comprising: obtaining a dynamic adaptive streaming over HTTP(DASH) video bitstream comprising one or more subpictures; determiningwhether the one or more subpictures include Versatile Video Coding (VVC)compliant subpictures; in response to the DASH video bitstream includingthe VVC compliant subpictures, annotating the one or more subpicturesbased on one or more flags; and manipulating the DASH video stream basedon the annotated one or more subpictures.